Stability of charged sulfur vacancies in 2D and bulk MoS2 from plane-wave density functional theory with electrostatic corrections
Stability of charged sulfur vacancies in 2D and bulk MoS2 from plane-wave density functional theory with electrostatic corrections
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DOI：
10.1103/physrevmaterials.4.064004
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发表时间：
2020-04
影响因子：
3.4
通讯作者：
A. M. Tan;C. Freysoldt;R. Hennig
中科院分区：
文献类型：
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作者：
A. M. Tan;C. Freysoldt;R. Hennig
二维半导体过渡金属二硫属化合物如MoS_2 ~$在光电子学、自旋电子学、光电子学和催化等领域有着广泛的应用前景。为了利用这些材料的电子器件的潜力，需要更好地了解缺陷如何控制载流子浓度，特性和迁移率。利用Freysoldt和Neugebauer开发的修正方案，以确保适当的静电边界条件，在二维材料中的带电缺陷，我们进行密度泛函理论计算单层和层状体MoS$_2$与硫空位的形成能和电荷跃迁能级。我们调查的收敛性，这些缺陷的性质相对于真空间距，面内超晶胞尺寸，和不同层次的理论。我们还分析了不同电荷状态下缺陷的电子结构，以深入了解缺陷对成键和磁性的影响。我们预测，这两个空缺结构进行Jahn-Teller扭曲，这有助于稳定的硫空位在$-1$带电状态。
Two-dimensional (2D) semiconducting transition metal dichalcogenides such as MoS$_2$ have attracted extensive research interests for potential applications in optoelectronics, spintronics, photovoltaics, and catalysis. To harness the potential of these materials for electronic devices requires a better understanding of how defects control the carrier concentration, character, and mobility. Utilizing a correction scheme developed by Freysoldt and Neugebauer to ensure the appropriate electrostatic boundary conditions for charged defects in 2D materials, we perform density functional theory calculations to compute formation energies and charge transition levels associated with sulfur vacancies in monolayer and layered bulk MoS$_2$. We investigate the convergence of these defect properties with respect to vacuum spacing, in-plane supercell dimensions, and different levels of theory. We also analyze the electronic structures of the defects in different charge states to gain insights into the effect of defects on bonding and magnetism. We predict that both vacancy structures undergo a Jahn-Teller distortion, which helps stabilize the sulfur vacancy in the $-1$ charged state.